Revoking mayorship is as easy as clicking one of two buttons: either dubbing the mayor as an employee or citing "other reasons," which could include cheating. According to Foursquare, most small business owners don't sign their businesses up for Foursquare because they don't want cheaters checking-in when they aren't really there, now they wield the power to regulate that phenomenon. Just remember: cheaters never prosper, so just work on that mayorship the right way.